A term arising from the 1950s denoting a high fidelity audio system. The term fell out of use after the advent of stereo, but is used today to denote a class of audio equipment above the mass market which reproduces audio faithful to the recording. The term is best used to differentiate real audiophile audio equipment from the myriad of clock radios, cheap home theater in boxes, and offcourse systems designed for listening to music of the urban persuasion.

Also (erroneously) short for "high fidelity" - used to describe recorded sound that sounds faithfully like the original production of the sound. It's a term that originated in the 1950's (before stereos) to describe sound-recording equipment that provided faithful reproductions, but nowadays is used mostly by audiophiles.

Fi: Hey there buddy!
You: Hi-Fi!

Pedophile: Come over here kiddie, these Bose speakers produce such high-fidelity sound!
Audiophile: No they don't.

(hi-fee) A person (usually a woman) who acts like her shit don't stink or she's too good for anyone. Also includes fasion lemings who'll wear whatever some womens rag will tell them to. Unoriginal botches...